These types of vibrators come in many versions and names like bullet, egg, mini, lipstick, pocket rocket, or palm.  What unifies them is their size.  Most bullets and minis are about 4 inches or less in length and generally intended for external stimulation only (ex: clitoris).  Being small, simple, and approachable, this category of vibrator is excellent for beginners.  These vibrators' size makes them perfect for discreet storage and travel.  Like some vibration during partner play?  Bullets and minis take away the awkward handling or presence of a large toy.   The advancement in engineering of controls and motors over the years have made bullets surprisingly powerful.  What was once a cute novelty that disappointed in power and lifespan is now a go-to and reliable orgasm generator for experienced toy users.  In our opinion, everybody should have a bullet/mini in their toybox!